/**
	This file is a part of the rexy/r0nk/atlas project
	Copyright (C) 2020 rexy712

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.	If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef REXY_DETAIL_MATRIX_HPP
#define REXY_DETAIL_MATRIX_HPP

#include <cstdlib> //size_t
#include <utility> //integer_sequence

namespace math::detail{

	template<size_t SW, size_t W = SW, size_t H = SW-1, size_t... Args>
	struct gen_id_tup {
		using tup = typename gen_id_tup<SW, W-1, H, Args..., 0>::tup;
	};
	template<size_t SW, size_t H, size_t... Args>
	struct gen_id_tup<SW,SW,H,Args...> {
		using tup = typename gen_id_tup<SW, SW-1, H, Args..., 1>::tup;
	};
	template<size_t SW, size_t H, size_t... Args>
	struct gen_id_tup<SW,0,H,Args...> {
		using tup = typename gen_id_tup<SW, SW, H-1, Args..., 0>::tup;
	};
	template<size_t SW, size_t... Args>
	struct gen_id_tup<SW,SW,0,Args...> {
		using tup = std::integer_sequence<size_t,Args...,1>;
	};


	template<size_t N, size_t... Args>
	struct gen_zero_tup {
		using tup = typename gen_zero_tup<N-1,Args...,0>::tup;
	};
	template<size_t... Args>
	struct gen_zero_tup<0,Args...> {
		using tup = std::integer_sequence<size_t,Args...>;
	};

	template<size_t W>
	struct id_initialization_matrix {
		using tuple = typename gen_id_tup<W>::tup;
	};


	template<size_t W, size_t H>
	struct default_initialization_matrix {
		using tuple = typename gen_zero_tup<W>::tup;
	};
	template<size_t W>
	struct default_initialization_matrix<W,W> {
		using tuple = typename id_initialization_matrix<W>::tuple;
	};

	template<typename T, size_t R>
	class mat_ref_obj
	{
	public:
		using size_type = size_t;

	protected:
		T* m_data = nullptr;
	public:
		constexpr mat_ref_obj(T* d, size_type i);
		constexpr T& operator[](size_type i);
		constexpr const T& operator[](size_type i)const;
	};

	template<typename T, size_t W, size_t H>
	class matrix_base
	{
		static_assert(W > 0, "Cannot have 0 columns matrix");
		static_assert(H > 0, "Cannot have 0 rows matrix");
	public:
		using value_type = T;
		using size_type = size_t;
		using pointer = value_type*;
		using const_pointer = const value_type*;
		using reference = value_type&;
		using const_reference = const value_type&;

		static constexpr size_type Columns = W;
		static constexpr size_type Rows = H;

	protected:
		value_type m_data[W*H];

	protected:
		template<size_type... Ss>
		constexpr matrix_base(std::integer_sequence<size_type,Ss...>);

	public:
		//Default construct as identity when square, zero otherwise
		constexpr matrix_base();

		//Range initializing constructors
		constexpr explicit matrix_base(detail::zero_initialize_t);
		constexpr explicit matrix_base(detail::no_initialize_t);
		template<typename U = void>
		constexpr explicit matrix_base(detail::id_initialize_t);

		//Value initializing constructors
		constexpr explicit matrix_base(value_type v);
		template<typename... Args>
		constexpr explicit matrix_base(Args&&... args);

		//Copying constructors
		constexpr matrix_base(const matrix_base&) = default;
		constexpr matrix_base(matrix_base&&) = default;
		template<typename U>
		constexpr matrix_base(const matrix_base<U,Columns,Rows>& m);
		~matrix_base() = default;

		//Assignement
		template<typename U>
		constexpr matrix_base& operator=(const matrix_base<U,Columns,Rows>& m);
		constexpr matrix_base& operator=(const matrix_base&) = default;
		constexpr matrix_base& operator=(matrix_base&&) = default;


		//Getters/Setters
		constexpr auto operator[](size_type x);
		constexpr auto operator[](size_type x)const;
		constexpr reference get(size_type x, size_type y);
		constexpr const_reference get(size_type x, size_type y)const;
		constexpr reference get(size_type i);
		constexpr const_reference get(size_type i)const;

		constexpr size_type columns()const;
		constexpr size_type rows()const;
		constexpr size_type size()const;

		constexpr pointer raw();
		constexpr const_pointer raw()const;
		constexpr operator pointer();
		constexpr operator const_pointer()const;

	};

}

#include "matrix.tpp"

#endif